Graphite nanofibers as catalyst support for proton exchange membrane fuel cells

By a ball-milling method, graphite nanofibers (GNF) were prepared from used carbon paper in proton exchange membrane fuel cells. The surface area of GNF was 229.3 m(2)/g. 20% platinum was loaded on the GNF and XC-72 to fabricate Pt/GNF and Pt/XC-72 supported catalysts. The results of cyclic voltammetry showed that the Pt/GNF catalyst had the same electrochemical surface area (ESA) as the Pt/XC-72 catalyst. The morphology of these catalysts was characterized by transmission electron microscopy. The electrochemical stability was measured for XC-72, GNF, Pt/XC-72, and Pt/GNF electrodes by the constant-potential oxidation. The peak current increased by 2% for GNF while 60% for XC-72. The corrosion current for Pt/XC-72 was 1.4 times of that for Pt/GNF. In addition, almost 84.7% ESA was lost for Pt/XC-72 catalyst after oxidation for 60 h, while only 37.2% ESA was lost for Pt/GNF. The results indicated that GNF possessed much higher resistance to electrochemical oxidation than XC-72.